The present inventions relate generally to the field of gas pressure regulators, and more specifically to a gas pressure regulator that includes a rugged or integral gauge.
Regulators are used to regulate the supply of many different gases for many different applications. One particularly important regulator application is oxygen pressure regulation in the healthcare field. Therefore, the inventions will be discussed in connection with oxygen regulators. It should be understood, however, that the present inventions are not limited to the healthcare field and are not limited to use with any particular gas, such as oxygen, but rather may be used with a wide variety of gases.
Regulators are designed to reduce a high source pressure to a working level. Portable tanks, also referred to as bottles, are typically used as oxygen sources in the healthcare field. Pressures in the tank can be as high as approximately 2200 p.s.i.g. in the U.S. and can reach approximately 3000 p.s.i.g. in Europe. Working pressures for oxygen for healthcare applications are normally approximately 50 p.s.i.g. in the U.S. and normally range between approximately 45 p.s.i.g. to 60 p.s.i.g. in Europe. In addition to reducing the source pressure to a working pressure, regulators also regulate the flow rate at which the oxygen is delivered. Two types of regulators are common: fixed flow regulators, which provide a multiple number of fixed flow rates from which a user may select, and variable flow regulators which allow infinite adjustment of the flow rate. Because fixed flow regulators are simple to use, they are mostly used in portable applications, such as in ambulances and home care. Variable flow regulators, on the other hand, are normally used in hospitals, outpatient and acute-care facilities and the like, where precise control over flow is important. Both types of regulators are typically supplied with a gauge for monitoring the gas source. When used with oxygen bottles, the gauge may indicate the source pressure, which provides an indirect indication of the amount of gas left in a bottle, or the gauge may directly indicate the amount of gas left in a bottle in a manner similar to an automobile gasoline gauge, i.e., by indicating empty, 1/4, 1/2, 3/4, or full.
Because fixed flow regulators are used in portable applications, durability is important. One problem that has plagued known portable regulators is damage to the gauge used to monitor the source pressure. Known regulators have gauges that typically protrude from the regulator body, making them susceptible to impact damage. Some known regulator arrangements attempt to protect the gauge from impact by encasing the gauge in a material such as rubber in order to decrease the severity of an impact. Another approach to this problem is to encase the gauge in a protective shield. Approaches such as these, while effective in protecting the external components of the gauge from shock to various degrees, are not as effective in protecting the internal components of the gauge. Most gauges in use today, such as the Bourdon-type gauge, have delicate internal components which may be damaged due to excessive vibration and/or impact to the regulator body as well as to the gauge itself. Even completely encapsulating the gauge with a protective shield cannot fully protect the internal components of such gauges.
Accordingly, there is a need for a regulator suitable for portable applications with a gauge that can better withstand vibration and impact.